[Gzz-commits] gzz/gfx libcolor/spaces.py libpaper/colors.py

[Janne V. Kujala]

CVSROOT:        /cvsroot/gzz
Module name:    gzz
Changes by:     Janne V. Kujala <address@hidden>        02/09/27 10:05:08

Modified files:
        gfx/libcolor   : spaces.py 
        gfx/libpaper   : colors.py 

Log message:
        Rewrite color sampling; the previous code produced only saturated colors

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/gzz/gfx/libcolor/spaces.py.diff?tr1=1.7&tr2=1.8&r1=text&r2=text
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/gzz/gfx/libpaper/colors.py.diff?tr1=1.9&tr2=1.10&r1=text&r2=text

Patches:
Index: gzz/gfx/libcolor/spaces.py
diff -c gzz/gfx/libcolor/spaces.py:1.7 gzz/gfx/libcolor/spaces.py:1.8
*** gzz/gfx/libcolor/spaces.py:1.7      Fri Sep 27 07:55:28 2002
--- gzz/gfx/libcolor/spaces.py  Fri Sep 27 10:05:08 2002
***************
*** 59,64 ****
--- 59,65 ----
          L = minL + (maxL - minL) * rnd.nextDouble()
          a = 200 * rnd.nextDouble() - 100
          b = 200 * rnd.nextDouble() - 100
+         # XXX: (a,b) is sampled from a square
          rgb = LABtoRGB([L,a,b])
      return rgb
  
***************
*** 74,101 ****
      rgb = [-1]
      L = minL + (maxL - minL) * rnd.nextDouble()
      ang = rnd.nextDouble() * 2 * math.pi
!     a = 100 * math.cos(ang)
!     b = 100 * math.sin(ang)
!     rgb = LABtoRGB([L,a,b])
! 
!     return LABclamp(rgb)
! 
! 
! def getRandomColor3(minL, maxL, hue_avg, hue_sd, rnd):
!     """Get a random color deterministically with Gaussian hue
! 
!     minL, maxL: minimum and maximum luminance value
!     hue_avg, hue_sd: hue distribution parameters in degerees
!     rnd: a random number generator, corresponding to
!       java.util.Random for the API. The same color
!       is always returned if the PRNG returns the
!       same list of values.
!     """
!     rgb = [-1]
!     L = minL + (maxL - minL) * rnd.nextDouble()
!     ang = (hue_avg + rnd.nextGaussian() * hue_sd) / 180 * math.pi
!     a = 100 * math.cos(ang)
!     b = 100 * math.sin(ang)
      rgb = LABtoRGB([L,a,b])
  
      return LABclamp(rgb)
--- 75,86 ----
      rgb = [-1]
      L = minL + (maxL - minL) * rnd.nextDouble()
      ang = rnd.nextDouble() * 2 * math.pi
!     r = rnd.nextDouble() * 100
!     # XXX: used to be "r = 100" producing only saturated colors!
!     # XXX: sampling saturation from the uniform distribution
!     # is not necessarily ideal
!     a = r * math.cos(ang)
!     b = r * math.sin(ang)
      rgb = LABtoRGB([L,a,b])
  
      return LABclamp(rgb)
Index: gzz/gfx/libpaper/colors.py
diff -c gzz/gfx/libpaper/colors.py:1.9 gzz/gfx/libpaper/colors.py:1.10
*** gzz/gfx/libpaper/colors.py:1.9      Wed Sep 25 10:00:19 2002
--- gzz/gfx/libpaper/colors.py  Fri Sep 27 10:05:08 2002
***************
*** 1,45 ****
  # Choosing colors and 3-dotproduct factors for papers.
  
! from gfx.libcolor.spaces import getRandomColor,getRandomColor2,RGBtoLAB
  
! from math import atan2,pi
  
  import java;
  
  class Colors:
      def _js(self, arg):
        return " ".join([str(a) for a in arg])
      def __init__(self, seed):
        rnd = self.rnd = java.util.Random(seed)
        # currently, 4 colors
        minlum = 80
  
!         # Just take alternating dark and light colors
!         while 1:
!             t = (100 - minlum)/2
!             col = [ getRandomColor2(minlum + t - t * (i & 1),
!                                     100 - t * (i & 1), rnd)
!                     for i in range(0,4) ]
!             if 120 - self._AB_angle(col) > 90 * rnd.nextFloat(): break
!             #if self._AB_angle(col) < 180: break
!         print "ANGLE=", self._AB_angle(col), "AREA=", self._AB_area(col)*100
! 
!         while 0:
!           col = [
!               getRandomColor2(minlum,100, rnd),
!               getRandomColor2(minlum,minlum + (100-minlum)*0.7, rnd),
!               getRandomColor2(minlum + (100-minlum)*0.7, 100, rnd),
!               # getRandomColor2(minlum + (100-minlum)*0.5, 100, rnd),
!           ]
!             #print self._AB_angle(col)
!             #print self._AB_avg_dot(col)
!             # if abdiff(col[0], col[1]) < 40: continue
!             #if abdiff(col0, col2) < 40: continue
!             #if abdiff(col0, col3) < 40: continue
!             #if abdiff(col1, col2) < 40: continue
!             #if abdiff(col1, col3) < 40: continue
!             # if abdiff(col[2], col[3]) < 40: continue
!             break
  
        self.colors = [self._js(c) for c in col]
  
--- 1,58 ----
  # Choosing colors and 3-dotproduct factors for papers.
  
! from gfx.libcolor.spaces import 
getRandomColor,getRandomColor2,RGBtoLAB,LABtoRGB,LABclamp
  
! from math import sin,cos,atan2,pi
! from random import shuffle
  
  import java;
  
+ dbg=0
+ 
  class Colors:
      def _js(self, arg):
        return " ".join([str(a) for a in arg])
      def __init__(self, seed):
        rnd = self.rnd = java.util.Random(seed)
+ 
        # currently, 4 colors
+         colors = 4
        minlum = 80
+         huerange = (45 + rnd.nextGaussian() * 45) * (pi / 180)
+ 
+         # Note: This color sampling scheme only produces
+         # palettes with similar colors.
+         # It could be nice to have other schemes
+         # with, e.g., complementary colors.
+         # (Note: color complementing should be done in RGB space)
+ 
+         # Sample hues uniformly from the range shifted to a random angle
+         hue0 = rnd.nextDouble() * 2*pi
+         hues = [hue0 + rnd.nextDouble() * huerange for i in range(0,colors)]
+ 
+         # Take one half dark colors and one half light colors
+         lumrange = 100 - minlum
+         lums = ([minlum + rnd.nextDouble() * lumrange/2
+                  for i in range(0,colors/2)] +
+                 [minlum + (1 + rnd.nextDouble()) * lumrange/2
+                  for i in range(colors/2,colors)]
+                 )
+ 
+         # Sample saturation:
+         #  - take the most saturated color 2/3 of the time
+         #    and a dull color 1/3 of the time
+         sats = [100 * (1 - (1 - (1 - rnd.nextDouble())**2) * 
(rnd.nextDouble() < .333))
+                 for i in range(0, colors)]
  
!         # Construct colors and clamp towards the CIELAB L-axis
!         # (keeping hue and luminance) to fit into the RGB cube
!         lab = [(lums[i], sats[i] * cos(hues[i]), sats[i] * sin(hues[i]))
!                for i in range(0,colors)]        
!         col = [LABclamp(LABtoRGB(c)) for c in lab]
!         shuffle(col, rnd.nextDouble)
!         
!         if dbg:
!             print "ANGLE=", self._AB_angle(col), "AREA=", 
self._AB_area(col)*100
  
        self.colors = [self._js(c) for c in col]